1. Field of the Invention
Embodiments of the present invention relate to a recording and/or reproducing apparatus and method with sector reallocation, and more particularly, to an apparatus and method with reallocation sector recovery for reducing the number of reallocation sectors by selectively recovering reallocation sectors.
2. Description of the Related Art
Embodiments of the present invention are related to technologies disclosed in Korea Patent Publication No. 2000-0047533 and U.S. Pat. No. 6,034,831.
Correspondingly, hard disc drives (HDDs) are a type of data storage device that record and/or reproduce data to/from a disc using a magnetic head. According to the recent trend for high capacities, higher densities, and greater compactness in HDDs, the number of bits per inch (BPI), denoting the recording density in a disc rotating direction, and the number of tracks per inch (TPI), denoting the recording density in a disc diameter direction, have increased. Accordingly, a more elaborate operation mechanism is required for HDDs.
A HDD may read and/or write data by rotating a disc at a constant speed rotation using a spindle motor, reading servo information of the disc at the same time interval using a transducer (head), and determining locations of data sectors based on the read servo information.
When a write error is generated, and a read operation in a specific condition is successfully performed thereafter, the HDD can reallocate an original sector to a substitute sector, e.g., in a spare cylinder area.
The maximum number of sectors which can be reallocated is limited and differs between HDDs. Therefore, when a reallocation request, exceeding the maximum number of sectors which can be reallocated, is generated, bad sectors are generated on a disc. Accordingly, the disc cannot operate normally.
A reallocation process can be initiated due to an external cause, such as an impact or vibration. However, not all generated reallocation sectors, generated due to external causes, actually correspond to a real reallocation condition.
According to the conventional methodologies, since there is no process for recovering reallocation sectors when the reallocation sectors have been generated because of temporary causes, such as an impact or vibrations, the number of reallocation sectors available becomes reduced. Therefore, since there are no more sectors available for substitution, when all of the reallocation sectors have been used due to the temporary external causes, a corresponding disc cannot operate normally upon the occurrence of bad sectors.